Reed contacts operable by magnetic forces



Aug. 18,1970 R. SCHE IDIG 3,525,060

REED CONTACTS OPERABLE BY MAGNETIC FORCES Filed May 17, 1968 7 INVENTOR A. sc HE/D/G ATTORNEY United States Patent Qifice 3,525,050 Patented Aug. 18, 1970 3,525,060 REED CONTACTS OPERABLE BY MAGNETIC FORCES Rudolf Scheidig, Stuttgart-Feuerbach, Germany, assignor to International Standard Electric Corporation, New York, N.Y.,. a corporation of Delaware Filed May 17, 1968, Ser. No. 729,991 Claims priority, application Ggrmany, May 26, 1967,

US. Cl. 335-153 4 Claims ABSTRACT OF THE DISCLOSURE At least two sets of contacts are arranged in a common reed tube. The contact elements of the same set each have different lengths. The operating air gap of the individual contact arrangements are provided in different planes intersecting the longitudinal axis of the reed tube, so that the contact sets can be actuated independently of each other by means of coils or permanent magnets.

The invention relates to sets of reed contacts operable by magnetic forces, whereby several sets of contacts are arranged in a common reed tube and wherein the contact elements per set are of different lengths.

Reed contacts in which several contact sets are provided either side by side or one above the other in a common reed tube are known and have been used for the through-connection of multi-wire communications in place of a plurality of individual reed contacts.

Also, it is known to arrange reed contact sets as switch-over contacts and make break contacts. Such arrangements may use contact elements of different lengths.

In all known arrangements of reed contacts comprising several contact elements 'Within a common reed tube, all contact sets in one reed tube that are enclosed by a common excitation coil or a common annular-shaped permanent magnet, can be operated only in common and not independently of each other.

Switching processes that require an actuation of contacts in a timed sequence could be achieved hitherto only with individual reed contacts, arranged side by side and staggered towards each other in their longitudinal direction. This type of actuation requires, where a permanent magnet is used, a correspondingly large and therefore expensive permanent magnet.

Where individual magnets for an electro-magnet actuation are arranged inside excitation coils, either a coil is required per contact or the coils used must be sufliciently large to encompass all of the reeds. However, the larger coils results in a considerable increase of the average length of winding so that, with equal power consumption of the excitation coils, the magnetic flux density drops. Thus, a higher excitation current in the coils is necessary in order to provide each reed contact the operating flux necessary for operating. Also, such arrangements are, of course, relatively insensitive; this insensitivity along with the larger space requirement for the individual contacts and the high production costs are disadvantageous in these arrangements.

Accordingly, it is an object of the present invention to avoid the disadvantages of the known arrangements by providing reed contact arrangements comprising a plurality of contact elements in a common reed tube. The contact elements are uniquely positioned to be actuated independently from each other either by electrical coils or by permanent magnets.

A related object of the present invention is to position the operating air gaps of the contact sets in the reed tubes in different planes intersecting the axis of the length of the reed tube.

According to a preferred embodiment of the invention at least two make-contact sets are provided within a reed tube. The contact sets are formed by an equal pair of contact elements whereby the movable contact element is relatively long and the stationary counter-contact is correspondingly short. The contact elements are inserted into the reed tube so that their operating air gaps are located at opposite ends of said reed tube.

According to another embodiment of the invention the contact elements are formed as blades. The movable blades have a constriction near the point of the elements entry into the tube. The constriction has defined resilient properties. The contact-making ends of the blades, on the other hand, may be reinforced, in order to obtain defined magnetic properties.

According to a further embodiment of the invention, the contact elements of the contact sets are designed as springs and pins with a round cross-section, respectively. The contact-making end of the movable spring is shaped in the form of a helix or a reinforced cup surrounding the stationary counter-contact pin.

Another embodiment of the invention provides that the contact elements face eath other as stationary contact pins, whereby one of the contact pins is connected with a contact-making piece, borne on a helical spring and moved through the magnetic field axially in the direction of the counter-contact pin.

According to another embodiment of the invention, the contact arrangements included in a reed tube are actuated in timely sequence by a shiftable permanent magnet par ticularly by an annular-shaped permanent magnet, enclosing the reed tube.

According to another embodiment of the invention, an electric coil is arranged in the plane determined by the position of each of the operating air gaps. The coils enclosing the reed tube and actuating the contact arrangements act either in cooperation with each other or independently, according to the circuitry of the excitation windings. Thereby, at least one coil may have an additional winding.

According to another embodiment of the invention, an electric coil is provided only at one end of the reed tube. The excitation of the coil operates the contact points at that end of the reed tube. In addition, the electromotive force moves an annular permanent magnet, sliding on the reed tube and supported by a spring. The magnets position depends on the excitation of the coil. The magnet operates the contacts provided at the opposite end of the reed tube.

The invention is not limited to designs comprising simple make-contacts. Also, switch-over contacts or makemake contacts may be used, as well as every desired combination of such contact arrangements may be inserted into the common reed tube as described above.

The reed contact arrangement described shows considerable advantages. Several contacts may be arranged in a common reed tube side by side or one above the other juxtaposed more closely than is possible for individual contacts. The costs per contact arrangement are reduced substantially and the production problems are minimized. The arrangement of the operating air gaps of the contacts within the reed tube in different planes, intersecting the longitudinal axis of the reed tube, permits a plurality of possible applications and circuits, partly mentioned in the description and shown on the drawings.

The above mentioned and other features and objects of this invention, and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of several embodiments of the invention taken in 3 conjunction with the following sectional drawings, wherein: 1

FIG. 1 shows a reed tube with blade-type armatures, actuated by a permanent magnet;

FIGS. 2 and 3 show diflerent designs of the Contact blades;

FIG. 4 shows another design of the reed contact with blade-type armatures, actuated by electric coils;

FIG. 5 shows a reed contact having contact armatures designed as springs or pins;

FIG. 6 shows another design of a reed contact, the contact armatures and stators designed as springs or pins respectively, actuated by an electric coil and by a permanent magnet; and

FIG. 7 shows a reed contact with stationary contact pins and a contact piece, borne in a helical spring, actuated by electric coils.

FIG. 1 shows a reed contact having within a common reed tube 1 two make-contacts. Each contact arrangement consists of a long contact blade 2 movable by the magnetic field, and a stationary short counter-contact blade 3. The contact blades are melted into the reed tube 1 in such a way that at one reed tube end a long, movable contact blade 2 is arranged beside a short, stationary contact blade 3. Thus, the operating air gaps within the reed tube 1 are staggered and the individual contact arrangements may be actuated independent of each other. The right hand contacts are shown operated by a movable permanent magnet which can be moved from the dotted line position to the full line position. In order to provide defined resilient properties for the long contact blades 2, said blades may be provided near the fixing point in the reed tube 1 with a constriction 4 (FIG. 2). Also, both blades 2 and 3 may be reinforced at their ends in order to obtain defined magnetic properties (FIG. 3).

Reed contact elements wherein the long contact blades 2 are provided with constrictions 4', are shown in FIG. 4. These contact elements have cooperating contact blades, or elements 3' which are located in one plane. The cooperating blades are, of course, not inserted into the reed tube 1 as shown on the drawing for a better view, but are inserted into the reed tube upright and side by side, in order to save space.

FIG. 5 shows another reed contact arrangement. Herein the contact elements are designed as springs or pins. Thereby the end of the long contact spring 5 of each contact set is helix-shaped and encloses the rigid or stationary counter-contact element pin 6. Such contact springs 5 ofler the advantage with respect to the production technique that the exactness required for melting them into the reed tube 1 is not as rigorous as for simple blade-type contacts.

FIG. 6 shows a reed contact similar to the one shown in FIG. 5, however, its long contact springs 5 are reinforced cup-shaped at their contact-making ends.

Another design of a reed contact arrangement is shown in FIG. 7. In this arrangement the contact elements inside the reed tube 1 face each other as fixed or stationary pins 7, 8. The longer pin of each contact arrangement is connected to a contact piece 10 via a helical spring 9. The piece 10 is moved through the magnetic field axially towards the counter-contact pin 8.

The designs of reed contacts described in the FIGS. 1 to 7 and other arrangements based upon the same principle of the staggered operating air gaps, may have switch-over contacts or make-make contacts, and may be actuated magnetically in the most varying way. For arrangements used with keys or push-buttons, the use of an annular-shaped permanent magnet 11 is suitable, such as shown in FIG. 1. The annular-shaped permanent magnet 11 slides on the reed tube 1 thereby alternatively operating one of the two contact arrangements in the reed tube 1. In such key-operated facilities, the switchover process depends on the speed of the moving magnet, therefore it would be disadvantageous to have to remove the permanent magnet 11 from abutting a ferromagnetic adhesive metal sheet 12. Based on the pressure exerted on the key or push-button the speed of the magnet and thus, the switch-over process can be predetermined.

Besides actuation by permanent magnets, the described reed contacts are also suitable for an electro-magnetic control of the individual contact arrangements. FIG. 7 shows an example of another contact wherein on planes 10 determined by the position of the operating air gaps, electric coils 13, 14 are arranged, enclosing the reed tube 1. Each coil 13 and 14 may be used for an independent actuation of the associated contact arrangement.

If, as shown in FIG. 4, one of the coils, e.g., 13', or both coils are provided with an additional winding 15, the most varied interdependent operations of the contacts arranged in the reed tube 1 may be attained according to the inter-connection of the individual windings.

Another possibility of a magnetic operation is shown in FIG. 6. The electric coil 13 actuates the contact :point,

arranged at its end of the reed tube 1, and an annularshaped permanent magnet 11 is slidably moved on the reed tube 1. The permanent magnet 11 is supported by a spring 16 and is moved against the force of the spring 16, if the coil 13 is excited in the opposite sense, thereby operating the other contact point.

While the principles of the invention have been described above in connection with specific apparatus and applications, it is to be understood that this description is made only by way of example, and not as a limitation on the scope of the invention.

What is claimed is:

1. A reed contact arrangement operable by magnetic forces,

said arrangement comprising a plurality of contact sets arranged in a common reed tube,

said contact sets each including a stationary element and a movable element,

said movable element of each set being relatively long,

said stationary element of each set being relatively short,

said contact making end of the movable element being shaped to enclose the contact making end of the stationary element,

each of said contact sets including operationing air and the operating air gaps being arranged in different planes intersecting the longitudinal axis of said reed tube with said air gaps being spaced apart and at opposite ends of said tube.

2. A reed contact arrangement operable by magnetic forces,

said arrangement comprising a plurality of contact sets arranged in a common reed tube,

each of said contact sets comprising a pair of contact elements,

each pair including a stationary contact element and a movable contact element,

each of said contact elements including an operating air gap,

the operating air gaps being in difiierent planes intersecting the longitudinal axis of said reed tube and at diiferent ends of said tube,

electric coil means arranged in the planes determined by the positions of the operating air gap and encircling the reed tube,

and said coil means comprising at least two coils whereby said contact sets can be operated interdependently or independently of each other according to the circuitry of said at least two coils.

3. The reed contact arrangement of claim 2 wherein at least one of the said coils possesses an additional windmg.

4. A reed contact arrangement operable by magnetic forces,

5 6 said arrangement comprising a plurality of contact sets References Cited arrangeim a comm reed UNITED STATES PATENTS each of sa1d contact sets COIl'lPl'lSlIlg a pair of contact elements, 1,603,289 10/1926 ONeill 335--196 X each of said pair of contact elements including a sta- 5 2,203,697 9 Vfi od e et a1.

tionary contact element and a movable contact ele- 2,709,723 1955 Tancfed 335196 X mam, 3,243,541 3/1966 DeFalco 335 154 each of said contacts including operating air gaps, 3,268,684 8/1966 Keller et the operating air gaps being arranged at different planes 3,3 ,593 /1967 Grengg 335-154 intersecting the longitudinal axis of said reed tube 10 3,348,174 10/1967 Scheidig 335-205 X and at opposite ends of said reed tube, an electrical coil provided only at one end of said reed FOREIGN PATENTS tube, 637,381 3/1962 ma an annular shaped permanent magnet provided surrounding said tube at the other end thereof, BERNARD A. GILH'EANY, Primary Examiner spring support means for slidably supporting said magnet on the reed tube whereby the contacts located ENVALL Asslstam Exammer at the coil end of said reed tube are actuated by ex- Us. CL citation of sa1d coil, and

said magnet being moved along said tube to actuate the said contacts at the magnet end of said tube responsive to said excitation of said coil. 

